Some males desire to be emasculated for no medical reason. These individuals are often secretive about their desires and little is known about their background and motivation.

We sought to characterize these modern eunuchs and to identify risk factors for genital self-mutilation or self-administered chemical castration.

We posted a questionnaire on the Eunuch Archive (http://www.eunuch.org) that was responded to by 135 voluntarily castrated males. Questionnaire data were supplemented by accompanying narrative responses and several personal interviews.

Participants answered questionnaire items pertaining to their knowledge about androgen deprivation, the nature of their castration, and the length of time between initial presentation of castration paraphilia and castration. These questionnaire data allowed us to compare and contrast voluntary chemical and physical eunuchs.

The physical castrations were largely premeditated, with an average of 18 years from the time that an individual developed interest in being a eunuch to the time of their actual castration. We identified four factors that may promote castration ideations: (i) abuse sustained during childhood, including parental threats of castration; (ii) homosexuality; (iii) exposure to animal castration during youth; and (iv) religious condemnation of sexuality. Chemical eunuchs were more likely to have sought castration for libido control or to advance transition from male to female (P  < 0.05). Physical eunuchs had a nonsignificant tendancy to have masochistic paraphilia involving genital mutilation in advance of their castration (P  < 0.1). Both Body Integrity Identity Disorder and Gender Identity Disorders occur among those who self-identify as eunuch.

We present evidence that the majority of self-identified voluntary eunuchs are not male-to-female transsexuals. Whereas the majority identify as male, many view themselves as in an alternate nonmale, nonfemale, gender space. We therefore suggest that male-to-eunuch is a valid transgender identity.